package com.xudow.app.pay.wx;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;
import android.util.Xml;

import com.tencent.mm.sdk.modelpay.PayReq;
import com.tencent.mm.sdk.openapi.IWXAPI;
import com.tencent.mm.sdk.openapi.WXAPIFactory;
import com.xudow.app.Config;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.xmlpull.v1.XmlPullParser;

import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Random;

import static com.xudow.app.util.LogUtils.makeLogTag;

/**
 * 微信支付
 */
public class WxPay {
    private final static String TAG = makeLogTag(WxPay.class);

    private Activity context;
    private PayReq req;
    private StringBuffer sb;
    private IWXAPI msgApi;
    private Map<String, String> resultunifiedorder;
    private String money;
    private String body;
    private String orderId;

    public WxPay(Activity context, String money, String body, String orderId) {
        super();
        this.context = context;
        this.money = money;
        this.body = body;
        this.orderId = orderId;
    }

    /**
     * 执行支付
     */
    public void start() {
        msgApi = WXAPIFactory.createWXAPI(context, null);
        sb = new StringBuffer();
        req = new PayReq();
        msgApi.registerApp(Config.WX_APPID);

        GetPrepayIdTask getPrepayId = new GetPrepayIdTask();
        getPrepayId.execute();
    }

    /**
     * 生成签名
     */
    private String genPackageSign(List<NameValuePair> params) {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < params.size(); i++) {
            sb.append(params.get(i).getName());
            sb.append('=');
            sb.append(params.get(i).getValue());
            sb.append('&');
        }
        sb.append("key=");
        sb.append(Config.WX_API_KEY);

        String packageSign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();

        return packageSign;
    }

    private String genAppSign(List<NameValuePair> params) {
        StringBuilder sb = new StringBuilder();

        for (int i = 0; i < params.size(); i++) {
            sb.append(params.get(i).getName());
            sb.append('=');
            sb.append(params.get(i).getValue());
            sb.append('&');
        }
        sb.append("key=");
        sb.append(Config.WX_API_KEY);

        this.sb.append("sign str\n" + sb.toString() + "\n\n");
        String appSign = MD5.getMessageDigest(sb.toString().getBytes()).toUpperCase();

        return appSign;
    }

    private String toXml(List<NameValuePair> params) throws UnsupportedEncodingException {
        StringBuilder sb = new StringBuilder();
        sb.append("<xml>");
        for (int i = 0; i < params.size(); i++) {
            sb.append("<" + params.get(i).getName() + ">");


            sb.append(params.get(i).getValue());
            sb.append("</" + params.get(i).getName() + ">");
        }
        sb.append("</xml>");

        return new String(sb.toString().getBytes(), "ISO8859-1");
    }

    private class GetPrepayIdTask extends AsyncTask<Void, Void, Map<String, String>> {

        private ProgressDialog dialog;


        @Override
        protected void onPreExecute() {
            dialog = ProgressDialog.show(context, "提示", "正在获取预支付订单...");
        }

        @Override
        protected void onPostExecute(Map<String, String> result) {
            if (dialog != null) {
                dialog.dismiss();
            }
            sb.append("prepay_id\n" + result.get("prepay_id") + "\n\n");
            resultunifiedorder = result;
            genPayReq();
        }

        @Override
        protected void onCancelled() {
            super.onCancelled();
        }

        @Override
        protected Map<String, String> doInBackground(Void... params) {
            String url = String.format("https://api.mch.weixin.qq.com/pay/unifiedorder");
            String entity = genProductArgs();

            byte[] buf = Util.httpPost(url, entity);

            String content = new String(buf);
            Map<String, String> xml = decodeXml(content);

            return xml;
        }
    }

    public Map<String, String> decodeXml(String content) {
        try {
            Map<String, String> xml = new HashMap<String, String>();
            XmlPullParser parser = Xml.newPullParser();
            parser.setInput(new StringReader(content));
            int event = parser.getEventType();
            while (event != XmlPullParser.END_DOCUMENT) {

                String nodeName = parser.getName();
                switch (event) {
                    case XmlPullParser.START_DOCUMENT:
                        break;
                    case XmlPullParser.START_TAG:
                        if ("xml".equals(nodeName) == false) {
                            xml.put(nodeName, parser.nextText());
                        }
                        break;
                    case XmlPullParser.END_TAG:
                        break;
                }
                event = parser.next();
            }

            return xml;
        } catch (Exception e) {
            Log.e(TAG, e.getMessage(), e);
        }

        return null;
    }

    private String genNonceStr() {
        Random random = new Random();
        return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());
    }

    private long genTimeStamp() {
        return System.currentTimeMillis() / 1000;
    }

    private String genOutTradNo() {
        Random random = new Random();
        return MD5.getMessageDigest(String.valueOf(random.nextInt(10000)).getBytes());
    }

    private String genProductArgs() {
        StringBuffer xml = new StringBuffer();

        try {
            String nonceStr = genNonceStr();
            xml.append("</xml>");
            List<NameValuePair> packageParams = new LinkedList<NameValuePair>();
            packageParams.add(new BasicNameValuePair("appid", Config.WX_APPID));
            packageParams.add(new BasicNameValuePair("body", body));
            packageParams.add(new BasicNameValuePair("mch_id", Config.WX_PAY_PARTNER_ID));
            packageParams.add(new BasicNameValuePair("nonce_str", nonceStr));
            packageParams.add(new BasicNameValuePair("notify_url", Config.WX_PAY_NOTIFY_URL));
            packageParams.add(new BasicNameValuePair("out_trade_no", orderId));
            packageParams.add(new BasicNameValuePair("spbill_create_ip", "127.0.0.1"));
            packageParams.add(new BasicNameValuePair("total_fee", money));
            packageParams.add(new BasicNameValuePair("trade_type", "APP"));

            String sign = genPackageSign(packageParams);
            packageParams.add(new BasicNameValuePair("sign", sign));

            String xmlstring = toXml(packageParams);

            return xmlstring;

        } catch (Exception e) {
            Log.e(TAG, e.getMessage(), e);
            return null;
        }
    }

    private void genPayReq() {
        req.appId = Config.WX_APPID;
        req.partnerId = Config.WX_PAY_PARTNER_ID;
        req.prepayId = resultunifiedorder.get("prepay_id");
        req.packageValue = "Sign=WXPay";
        req.nonceStr = genNonceStr();
        req.timeStamp = String.valueOf(genTimeStamp());

        List<NameValuePair> signParams = new LinkedList<NameValuePair>();
        signParams.add(new BasicNameValuePair("appid", req.appId));
        signParams.add(new BasicNameValuePair("noncestr", req.nonceStr));
        signParams.add(new BasicNameValuePair("package", req.packageValue));
        signParams.add(new BasicNameValuePair("partnerid", req.partnerId));
        signParams.add(new BasicNameValuePair("prepayid", req.prepayId));
        signParams.add(new BasicNameValuePair("timestamp", req.timeStamp));

        req.sign = genAppSign(signParams);

        sb.append("sign\n" + req.sign + "\n\n");

        sendPayReq();
    }

    private void sendPayReq() {
        msgApi.registerApp(Config.WX_APPID);
        msgApi.sendReq(req);
    }

    /**
     * 判断微信是否已经安装
     *
     * @return
     */
    public static boolean isWXAppInstalledAndSupported(Context ctx) {
        IWXAPI msgApi = WXAPIFactory.createWXAPI(ctx, null);
        msgApi.registerApp(Config.WX_APPID);

        boolean sIsWXAppInstalledAndSupported = msgApi.isWXAppInstalled()
                && msgApi.isWXAppSupportAPI();

        return sIsWXAppInstalledAndSupported;
    }
}
